Expoxy/acid anhydride composition

ABSTRACT

An epoxy/acid anhydride composition characterized by containing, as a curing accelerator, a substituted triazine of the formula [I] ##STR1## (wherein X is an amino group, C 1-18  monoalkylamino group, di C 1-18  alkylamino group, morpholino group, piperidino group, methyl group or phenyl group; R 1  and R 2  independently each represent C 1-12  alkyl group, C 1-12  hydroxyalkyl group, C 4-8  cycloalkyl group, C 5-9  cycloalkylmethyl group or C 5-9  methylcycloalkyl group) in an epoxy/acid anhydride composition in which an epoxy compound and an acid anhydride-curing agent are contained, and an epoxy/acid anhydride resin composition prepared by thermosetting the epoxy/acid anhydride composition.

TECHNICAL FIELD

The present invention relates to an epoxy-based resin composition,particularly, an epoxy/acid anhydride composition which hasquick-curability and storage stability for a long term, and anepoxy/acid anhydride resin composition prepared by thermosetting theepoxy/acid anhydride composition. The epoxy/acid anhydride compositionof the present invention is useful for an improvement of workability incuring and physical properties for casting materials, laminatingmaterials, molding compound for encapsulation, resin for embedding,adhesives, and coatings, etc.

BACKGROUND ART

An epoxy resin has been widely employed as adhesives, coatings, castingmaterials, molding compound for encapsulation, resin for embedding, andlaminating materials because of an excellent adhesive property withmetallic materials and glass, high mechanical strength, and excellentworkability in curing, etc.

An epoxy resin is designed as being cured by mixing with an amine-curingagent, a mercaptan-curing agent, a phenol resin-curing agent, and anacid anhydride-curing agent in response to the uses of the epoxy resin,and those are occasionally employed together with a tertiary amine-,quaternary ammonium-, tertiary phosphine-, imidazole-, and azabicyclocompound-curing accelerator as a catalyst for the purpose of theaddition of curability at low temperature and curability in a short timeof period, etc.

In recent years, requirements for an improvement in characteristics havebecome more advanced in a variety of utilization fields for a curedarticle prepared from an epoxy resin. In the system in which anamine-curing agent is contained, there also increase fields in whichcharacteristics cannot be satisfied by conventional products because ofa problem such as storage stability for a long term caused by a greatchange of viscosity after the amine-curing agents are contained.Further, in a system which employs an acid anhydride- or phenolresin-curing agent, etc, there is a similar problem in curingaccelerators mainly employed until now, which include tertiary amine-,quaternary ammonium-, tertiary phosphine-, quaternary phosphonium-,imidazole-, and azabicyclo compound-ones. For solving the problem, ithas been proposed a modified epoxy adduct, a modified aliphatic amine, amodified polyamide amine, a mannich-modified amine, a thiourea-modifiedamine, a Schiff-modified amine (obtained by ketiminization), a Michaeladdition-modified amine, and a quaternary salt of imidazoles, etc.

There is an attempt that an N-substituted melamine is employed as anamine-curing agent for improving a storage stability after mixing andworkability, etc. As such epoxy resin compositions, Japanese PatentApplication Laid-open No. Sho 56-72019 discloses an epoxy resincomposition in which an N-substituted melamine is contained. BritishPatent No. 1192790 discloses an epoxy resin composition in which anN-substituted melamine having at least two primary amino groups orguanamine, etc. is contained as an amine-curing agent.

There is an attempt that an N-substituted melamine is employed as acuring accelerator in an epoxy compound/phenol resin curing system forimproving a stability such as a pot life after mixing and workability.As such epoxy resin compositions, Japanese Patent Application Laid-openNo. Sho 60-202117 discloses an epoxy resin composition in which anN-substituted melamine and a novolak-type phenol resin are contained.

In the case of preparing an epoxy compound/acid anhydride-cured resin,if a tertiary amine-, a quaternary ammonium-, a quaternary phosphonium-,imidazole-, and azabicyclo compound-curing accelerators, etc. are notcontained, reactivity of an epoxide with an acid anhydride is poor,productivity exceedingly lowers in a cured resin, and it becomessubstantially difficult to prepare the cured resin. However, if such thecuring accelerator is employed together as a catalyst, reaction usuallyproceeds even at a relatively low temperature, viscosity increases witha lapse of time and, further, gelling is caused, resulting in that acomposition becomes incapable of employing.

Further, as a method for prolonging a pot life, although there is ameans in which a very small amount of the above-mentioned curingaccelerator or a curing accelerator having a low activity is employed,it is apt to cause defects such as bubbles and cracks, etc,particularly, in a curing reaction at high temperatures.

In the above-mentioned British Patent No. 1192790, it is disclosed anepoxy compound/acid anhydride-curing resin system and an epoxycompound/amine-curing resin system, and it is disclosed an epoxy resincomposition in which an N-substituted melamine having at least twoprimary amino groups or guanamine, etc. is mixed as an amine-curingagent together with a benzoyl urea- and a sulfonyl urea-curingaccelerator. In the curing resin systems, it is exemplified that theN-substituted melamine having at least two primary amino groups orguanamine, etc. shows an excellent property, and in Examples for theacid anhydride-curing system, it is disclosed a combination with thebenzoyl urea- or sulfonyl urea-curing accelerator.

The present invention uses an acid anhydride-curing agent in an epoxycompound and contain a substituted triazine compound having a specifiedstructure in a limited amount as a curing accelerator, whereby aiming toprovide an epoxy/acid anhydride composition which is excellent in a potlife after the curing agent is contained, storage stability, andworkability, and an epoxy/acid anhydride resin composition prepared bythermosetting the epoxy/acid anhydride composition, and in which defectssuch as bubbles and cracks are not caused in a cured resin at all.

DISCLOSURE OF THE INVENTION

The present invention relates to an epoxy/acid anhydride compositioncharacterized by containing, as a curing accelerator, a substitutedtriazine of the formula [I] ##STR2## (wherein X is an amino group, C₁₋₁₈monoalkylamino group, di C₁₋₁₈ alkylamino group, morpholino group,piperidino group, methyl group or phenyl group; R¹ and R² independentlyeach represent C₁₋₁₂ alkyl group, C₁₋₁₂ hydroxyalkyl group, C₄₋₈cycloalkyl group, C₅₋₉ cycloalkylmethyl group or C₅₋₉ methylcycloalkylgroup) in an epoxy/acid anhydride composition in which an epoxy compoundand an acid anhydride-curing agent are contained, and an epoxy/acidanhydride resin composition prepared by thermosetting the epoxy/acidanhydride composition.

Hereinafter, the present invention will be described in detail.

As the epoxy compound to be employed in the present invention, it ispreferable to contain at least two epoxy groups in the molecule from aviewpoint of heat resistance and mechanical strength in a cured resin.Of the epoxy compound having two epoxy groups, a bisphenol A-epoxy resinprepared by a reaction of bisphenol A with epichlorohydrine, a bisphenolF-epoxy resin prepared by a reaction of bisphenol F withepichlorohydrine, and a bisphenol S-epoxy resin prepared by a reactionof bisphenol S with epichlorohydrine, etc. are exemplified, and they arepreferable to have molecular weight of 300 to 5000. As the epoxycompound having at least three epoxy groups, a novolak-epoxy resinprepared by a reaction of a phenol novolak resin or a cresol novolakresin with epichlorohydrin, triglycidylisocyanurate,tris(α-methylglycidyl) isocyanurate,tris(β-methylglycidyl)-isocyanurate,tris(hydroxyphenyl)methanetriglycidyl ether,1,3,5-tri(glycidyloxy)benzene, triglycidylester of 1,3,5-trimesic acid,tetraglycidylxylenediamine, tetraglycidylamino-diphenylmethane, andtetrakis(4-hydroxyphenyl) ethane tetraglycidylether, etc. areexemplified. Further, in order to reduce viscosity in a composition andto give flexibility to a cured resin, glycol diglycidylethers such as aneopentylglycol diglycidylether, a hexamethyleneglycol diglycidylether,etc., polyoldiglycidylethers such as a polyethyleneglycoldiglycidylether, a polypropyleneglycol diglycidylether as analiphatic-epoxy compound having two epoxy groups can be used together,and polyolpolyglycidyl-ethers such as glycerine polyglycidylether,pentaerythritol polyglycidylether, trimethylolpropane polyglycidylether,etc. as an aliphatic-epoxy resin having three or more epoxy groups canbe used together.

Since an epoxy compound having one epoxy group such asphenylglycidylether and butylglycidylether lowers a crosslinkingdensity, the amount to be used must be limited so that the number ofepoxy groups in the epoxy compounds becomes at least 2 on an average.

As the acid anhydride to be employed in the present invention, it ispreferable to use an acid anhydride having one acid anhydride group inthe molecule such as phthalic anhydride, tetrahydrophthalic anhydride,hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride,methylhexahydrophthalic anhydride, nadic anhydride, methylnadicanhydride, maleic anhydride, succinic anhydride, octylsuccinicanhydride, and dodecenylsuccinic anhydride. Further, an acid anhydridehaving two acid anhydride groups in the molecule such as pyromelliticanhydride, cyclobutane tetracarboxylic anhydride, naphthalenetetracarboxylic anhydride, and tetralin-dicarboxylic anhydride, and anacid anhydride having one acid anhydride group and one carboxylic groupin the molecule such as trimellitic anhydride have usually a highmelting point, and those are poor in solubility into epoxy compounds andsolvents, etc., whereby, resins are apt to become unequal in a curingreaction. Accordingly, the use quantity is limited within a quantitycapable of uniformly copolymerizing in a system, and it is preferablynot more than 10% by weight based on the total weight of the acidanhydrides.

Mixing ratio of the above-mentioned epoxy compounds to the acidanhydrides is 0.7 to 1.2 equivalent, preferably 0.8 to 1.1 equivalent,and more preferably 0.9 to 1.0 equivalent of acid anhydride group basedon 1 equivalent of epoxy group.

As the substituted triazine employed which is a curing accelerator foran epoxy resin to be employed in the present invention, compounds havingat least two secondary amino groups as shown in the formula [I] and alsocontaining any one of a various kinds of functional groups describedbelow are preferable.

That is, X is amino group, monoalkylamino group of alkyl group having 1to 18 carbon atoms, dialkylamino group of alkyl group having 1 to 18carbon atoms, morpholino group, piperidino group, methyl group or phenylgroup. Of the groups, amino group, monoalkylamino group having 1 to 12carbon atoms, dialkylamino group having 1 to 12 carbon atoms orpiperidino group are more preferable.

In R¹ and R² as the secondary amino group, in a case of alkyl grouphaving 1 to 12 carbon atoms, said group may be straight-chain orbranched and alkyl group hving 1 to 9 is more preferable; in a case ofhydroxyalkyl group having 1 to 12, said group may be straight-chain orbranched and the position of the hydroxy group is not particularlylimited and alkyl group having 1 to 9 is more preferable; in a case ofcycloalkyl group having 4 to 8 carbon atoms, cyclopentyl group orcyclohexyl group is more preferable; in the case of cycloalkylmethylgroup having 5 to 9 carbon atoms, methyl-cyclobutyl group,methylcyclopentyl group, methylcyclohexyl group, methylcycloheptyl groupor methylcyclooctyl group are exemplified, and cyclopentylmethyl groupor cyclohexylmethyl group are more preferable; in the case ofmethylcycloalkyl group having 5 to 9 carbon atoms, methylcyclobutylgroup, methyl cyclopentyl group, methylcyclohexyl group,methylcyclo-heptyl group or methylcyclooctyl group are exemplified, andcyclopentylmethyl group or cyclohexylmethyl group is more preferable.These substituted triazines may be used solely or in combination.

The substituted triazine shown by the formula [I] to be employed in thepresent invention can be readily prepared by a publicly knownconventional method. For example, it includes a method described inJournal of American Chemical Society (J. Am. Chem. Soc.), vol. 73, page2984, 1951, in which a 2-chloro-1,3,5-triazine derivative is allowed toreact with an alkyl amine hydrochloride, a method described inChemishe-Berichte (Chem Ber.), vol. 18, page 2755, 1885, in which a2,4,6-trimethylthio-1,3,5-triazine derivative is allowed to react withan alkyl amine, a method described in U.S. Pat. No. 2,228,161, 1941, inwhich 2,4,6-triamino-1,3,5-triazine is allowed to react with an alkylamine hydrochloride, and a method described in German Patent No.889,593, 1953, in which 2-piperidino-4,6-diamino-1,3,5-triazine isobtained by allowing to react cyanopiperidine with cyanoguanidine, and amethod described in Japanese Patent Application Laid-open No. Hei3-215564, in which cyanuric chloride is allowed to react withcorresponding alkyl amines.

Further, following methods are raised, i.e., a method described inJapanese Patent Application No. Hei 6-166618, in which a 1,3,5-triazinederivative is allowed to react with an alcohol in the presence of acatalyst of group VII or group VIII in periodic table, a methoddescribed in Japanese Patent Application No. Hei 6-280370, in which a1,3,5-triazine derivative is allowed to react with an alcohol in thepresence of a catalyst of group VII or group VIII in the periodic tableand a hydrogen-containing gas, and a method described in Japanese PatentApplication No. Hei 6-292791, in which a 1,3,5-triazine derivative isallowed to react with an olefine in the presence of a catalyst of groupVII or group VIII in the periodic table and a carbon monoxide/hydrogenmixed gas, etc. These Japanese patent applications were filed in Japanby the present applicant. Although the substituted triazine may beprepared by these methods or any method, in the case that it is employedin fields of electronic materials, it is preferable to obtainsubstituted triazines by using a method for reacting melamine havingless hydrolyzable chlorine which is retained in the substitutedtriazine, with alcohols under the presence of a specified catalyst, amethod for reacting a melamine with aldehydes under the presence of aspecified catalyst in a hydrogen atmosphere, and a method for reactingof a melamine with olefines under the presence of a specified catalystin a hydrogen/carbon monoxide atmosphere.

Such the substituted triazines specifically include 2-amino-4-(mono-2-hydroxyethyl )amino-6-monoethylamino- 1,3,5-triazine,2-amino-4,6-bis(monoethylamino)-1,3,5-triazine,2-amino-4,6-bis(monobutylamino)-1,3,5-triazine,2-amino-4,6-bis(monocyclohexylamino)-1,3,5-triazine,2-amino-4,6-bis(monocyclohexylmethylamino)-1,3,5-triazine,2-amino-4,6-bis(methylcyclohexylamino)-1,3,5-triazine,2-amino-4,6-bis(mono-2-ethylhexylamino)-1,3,5-triazine,2-amino-4,6-bis(monododecylamino)-1,3,5-triazine,2,4-bis(mono-2-hydroxyethylamino)-6-methyl-1,3,5-triazine,2,4-bis(monoethylamino)-6-methyl-1,3,5-triazine,2,4-bis(monobutylamino)-6-methyl-1,3,5-triazine,2,4-bis(monocyclohexylamino)-6-methyl-1,3,5-triazine,2,4-bis(mono-2-ethylhexylamino)-6-methyl-1,3,5-triazine,2,4-bis(monododecylamino)-6-methyl-1,3,5-triazine,2,4-bis(mono-2-hydroxyethylamino)-6-phenyl-1,3,5-triazine,2,4-bis(monoethylamino)-6-phenyl-1,3,5-triazine,2,4-bis(monobutylamino)-6-phenyl-1,3,5-triazine,2,4-bis(monocyclohexylamino)-6-phenyl-1,3,5-triazine,2,4-bis(mono-2-ethylhexylamino)-6-phenyl-1,3,5-triazine,2,4-bis(monododecylamino)-6-phenyl-1,3,5-triazine,2,4,6-tris(monoethylamino)-1,3,5-triazine,2,4,6-tris(mono-2-hydroxyethylamino)-1,3,5-triazine,2,4,6-tris(monoisopropylamino)-1,3,5-triazine,2,4,6-tris(butylamino)-1,3,5-triazine,2,4,6-tris(monocyclohexylamino)-1,3,5-triazine,2,4,6-tris(mono-2-ethylhexylamino)-1,3,5-triazine,2,4,6-tris(monododecylamino)-1,3,5-triazine,2,4-bis(monoethylamino)-6-diethylamino-1,3,5-triazine,2,4-bis(mono-2-hydroxyethylamino)-6-di(mono-2-hydroxyethyl)-amino-1,3,5-triazine,2,4-bis(butylamino)-6-dibutylamino-1,3,5-triazine,2,4-bis(monocyclohexylamino)-6-dibutylamino-1,3,5-triazine,2,4-bis(mono-2-ethylhexylamino)-6-dibutylamino-1,3,5-triazine,2,4-bis(monododecylamino)-6-di(mono-2-ethlyhexyl)amino-1,3,5-triazine,2,4-bis(2-hydroxyethylamino)-6-piperidino-1,3,5-triazine,2,4-bis(monoethylamino)-6-piperidino-, 1,3,5-triazine,2,4-bis(monobutylamino)-6-piperidino-1,3,5-triazine,2,4-bis(monocyclohexylamino)-6-piperidino-1,3,5-triazine,2,4-bis(mono-2-ethylhexylamino)-6-piperidino-1,3,5-triazine,2,4-bis(monododecylamino)-6-piperidino-1,3,5-triazine,2,4-bis(mono-2-hydroxyethylam ino)-6-morpholino-1,3,5-triazine,2,4-bis(monoethylamino)-6-morpholino-1,3,5-triazine,2,4-bis(monobutylamino)-6-morpholino-1,3,5-triazine,2,4-bis(monocyclohexylamino)-6-morpholino-1,3,5-triazine,2,4-bis(mono-2-ethylhexylamino)-6-morpholino-1,3,5-triazine, and2,4-bis(monododecylamino)-6-morpholino-1,3,5-triazine, etc.

The substituted triazine shown in the formula [I] is preferably mixed ina quantity of 0.1 to 5 parts by weight, and more preferably 0.2 to 3parts by weight based on 100 parts by weight of the epoxy compounds.

Curing reaction in thus-mixed epoxy/acid anhydride composition of thepresent invention may be carried out in a condition of either theabsence of solvents such as casting materials or the presence ofappropriate organic solvents such as coatings, varnishes, and varnishesfor impregnation in laminating. In the case that the organic solventsare employed, ketone-solvents such as methylisobutyl ketone,ester-solvents such as butylacetate, ether-solvents such as dioxane,alcohol-solvents such as butanol, Cellosolve-solvents such as butylCellosolve, Carbitol-solvents such as butylcarbitol, aromatichydrocarbon-solvents such as toluene and xylene, amide-solvents such asdimethyl formamide and dimethyl acetamide, sulfoxide-solvents such asdimethyl-sulfoxide, and pyrrolidone-solvents such asN-methylpyrrolidone, etc. are exemplified.

If the curing reaction is not remarkably hindered, any solvents may beemployed.

Temperature in the curing reaction is preferably 80 to 250° C., and morepreferably 100 to 220° C. In the case that a solvent having a lowboiling point is employed, an autoclave and the like is used andreaction can be carried out at 80 to 250° C., and preferably 100 to 220°C. under pressure of 2 to 100 kg/cm². Also, the temperature may bemaintained at a fixed temperature until the completion of the reaction,and may be carried out while elevating the temperature in a fixed speedwith the progress of the reaction. Further, it may be intermittentlyelevated in multiple stages, for example, such as 100° C.×1 hour → 150°C.×3 hour → 200° C.×5 hour . . . , that is, it is a method for curing ata high temperature after a change to a B stage or oligomer at arelatively low temperature.

Still further, a small quantity of optional components can be furthermixed so far as the aim of the present invention is attained, whichinclude a variety of additives such as, for example, a silicone oil-,amide- and ester-defoaming agent, a hindered phenol- and hinderedamine-stabilizer, metal soap such as a stearate, a silicone resin- andfluorine resin-release agent in response to purposes, whereby obtaininga further preferred epoxy resin composition having heat resistance.

(Effects)

As an epoxy resin composition composed of an epoxy compound and asubstituted triazine, Japanese Patent Application Laid-open No. Sho56-72019 discloses an epoxy resin composition in which an N-substitutedmelamine having a triazine skeltone is contained. This publication showsan example that a substituted melamine is applied as an amine-curingagent. In a usual amine-curing agent, it is publicly known that althoughit is depending upon a mixing ratio, not only an addition reaction of anepoxy group with an amino hydrogen in the primary amino group or asecondary amino group is caused, but also an addition reaction of anepoxy group with OH group and an anion polymerization reaction betweenepoxy groups is caused. Since a reaction of an epoxy compound with anN-substituted melamine is also identical to the reactions, a bondingmode in the polymers is an amine bond and/or an ether bond.

Further, as an example in which an N-substituted melamine is employed asa curing accelerator for an epoxy compound/phenol resin curing system,Japanese Patent Application Laid-open No. Sho 60-202117 discloses anepoxy resin composition in which a novolak type phenol resin and a smallquantity of an N-substituted melamine are contained. In this example, anaddition reaction of epoxy group with a phenolic OH group is a primaryreaction, and a bonding mode in the polymers is an ether bond.

On the other hand, in a curing reaction in an epoxy/acid anhydridecomposition, an addition reaction of epoxy group with acid anhydridegroup is a primary reaction, and a bonding mode in the polymers is anester bond. The curing systems for epoxides are selected inconsideration of uses or requirements in properties.

In the case that the epoxy/acid anhydride composition is cured, if acuring accelerator is not mixed as a catalyst, a reactivity of anepoxide with an acid anhydride is poor, productivity for a cured resinexceedingly lowers, and it becomes substantially difficult to preparethe cured resin. As such the curing accelerator, tertiary amines,quaternary ammoniums, tertiary phosphines, quaternary phosphoniums,imidazoles, and azabicyclo-compounds, etc. are examplified. However, ifthe curing accelerators are employed together as a catalyst, a reactionusually progresses even at relatively low temperatures, and viscosityincreases with a lapse of time in storage, resulting in that acomposition becomes incapable of using by gelation. The curingaccelerators include many kinds, and although a resin can be morequickly cured by an accelerator having a higher reactivity, stabilityafter mixing becomes exceedingly lower and, contrarily, although anaccelerator having a lower reactivity shows more excellent stability, acuring reaction in a resin becomes slower, resulting in thatproductivity of a cured article becomes lower.

As a fact which cannot be quite supposed in an investigation up to now,it was found that in the epoxy/acid anhydride composition of the presentinvention in which a specified substituted triazine is contained as acuring accelerator, although the reason is not always clear, stabilityafter such a triazine is contained is exceedingly excellent and a curingreaction is sufficiently quick, resulting in that productivity of acured article is excellent, and, as a result of an intensiveinvestigation, the present invention has been completed.

The substituted triazine to be employed in the present invention isshown by the formula [I]. However, in the formula [I], in the case ofmelamine in which X is an amino group, and R¹ and R² are all a hydrogen;acetoguanamine in which X is a methyl group, and R¹ and R² are all ahydrogen; benzoguanamine in which X is a phenyl group, and R¹ and R² areall a hydrogen; N,N-dialkylmelaimine in which X is an N,N-dialkylaminogroup, and R¹ and R² are all a hydrogen;2,4-diamino-6-piperidino-1,3,5-triazine in which X is a piperidinogroup, and R¹ and R² are all a hydrogen; and2,4-diamino-6-morpholino-1,3,5-triazine in which X is a morpholinogroup, and R¹ and R² are all a hydrogen, etc., and in the case that thetriazine contains 2 to 3 primary amino groups and no secondary aminogroups, activity is short and inferiority of curing is caused. Moreover,in the case of curing at a high temperature, a reaction is rapidlycaused, resulting in that bubbles and cracks are occasionally causedbecause of an unhomogenized reaction and rapid evaporation of volatilecomponents. Further, also in the case of a tetra-alkylatedacetoguanamine, a tetra-alkylated benzoguanamine, and a hexa-alkylatedmelamine which have at least two tertiary amino groups and no secondaryamino groups, the same results are caused. Still further, in the casethat X is a mono alkylamino group, and R¹ and R² are all a hydrogen,that is, also in a mono-alkylated melamine and a penta-alkylatedmelamine which have one secondary amino group, the same results arecaused.

From the above results, it can be readily understood that a secondaryamino group such as a monoalkylamino group and a mono(hydroxyalkyl)amino group becomes a center position at which an activityis generated as a curing accelerator for the substituted triazine to beemployed in the present invention. The reason is not always clear. Forexample, it is supposed that in the case of a hexa-alkylated melamineand a tetra-alkylated benzoguanamine, etc., although those are regardedas a kind of tertiary amines, steric hindrance is stronger incircumference of nitrogen atoms compared to general tertiary aminesbecause of the structure of the tertiary amine connected directly with atriazine ring. Further, it is supposed that although a triazine havingat least two primary amino groups has an inherent characteristic of atriazine, it does not have a characteristic as an amine, and areactivity to an epoxide and an acid anhydride is too weak.

Still further, it is supposed that although a triazine having at leasttwo secondary amino groups has an inherent characteristic as a triazine,not only it has a characteristic as an amine, but also steric hindranceis weaker compared to a hexa-alkylated melamine and a tetra-alkylatedbenzoguanamine, etc., resulting in that those show an excellentcharacteristic.

It is to be noted that GB Patent No. 1192790 discloses an epoxy resincomposition in which an N-substituted melamine having at least twoprimary amino groups or guanamine, etc. is mixed as an amine-curingagent together with a benzoyl urea- and sulfonyl urea-curingaccelerator. In the composition, it is exemplified that theN-substituted melamine having at least two primary amino groups orguanamine, etc. shows an excellent property. However, in Examples forthe acid anhydride-curing system, it is only disclosed a combinationwith the benzoyl urea- and sulfonyl urea-curing accelerator, in whichany disclosures with respect to the present invention is not made.

In a mixing ratio in the respective components, a ratio between theabove-mentioned epoxy compounds and the acid anhydrides is 0.7 to 1.2equivalent, preferably 0.8 to 1.1 equivalent, and more preferably 0.9 to1.0 equivalent of an acid anhydride group based on 1 equivalent of anepoxy group. In the case of less than 0.7 equivalent, there is a problemthat a cured article becomes apt to be colorated, and crosslinkingdensity lowers. Although the reason is not always clear, it is supposedthat there becomes apt to be caused a side reaction such as apolymerization reaction between epoxy groups. Contrarily, in the case ofexceeding 1.2 equivalent, unreacted acid anhydride groups and carboxylicgroups derived therefrom increase in a cured article, resulting in thata water absorption property becomes larger in a cured article, and therebecomes lower chemical resistance against alkalis, etc., and if it isapplied for electronic materials, it causes a decline of insulationresistance, etc.

The substituted triazine shown in the formula [I] is preferablycontained in a quantity of 0.1 to 5 parts by weight, and more preferably0.2 to 3 parts by weight based on 100 parts by weight of the epoxycompounds. In the case of less than 0.1 part by weight, reactivitycannot be sufficiently obtained in curing and, contrarily, in the caseof exceeding 5 parts by weight, storage stability becomes lower afterthe triazine is contained.

In the case that the above-mentioned curing reaction is carried out in asolution, solvents are not particularly limited so far as notobstructing the curing reaction. In the case of a polymerization bycasting into a mold, it is preferable to use a solvent capable ofreadily removal before casting, and in the case of a varnish for aimingat coating, it is preferable to use a solvent capable of readily dryingor evaporating at reduced pressure. As the solvents being apt to readilyobstruct the curing reaction, a carboxylic acid-solvent and a solventhaving phenolic hydroxyl groups are exemplified. Even in the case thatthe solvents are unavoidably employed, those are preferably employed ina quantity of not more than 1 part by weight based on 100 parts byweight of the epoxy compounds. Further, a primary or secondaryamine-solvent should not be mixed at all because of remarkablyaccelerating a change with a lapse of time by an exceedingly largereactivity with an epoxide and an acid anhydride, and an exceedinglylarge catalytic activities.

Hereinafter, there are illustrated preferred embodiments in the presentinvention.

1. An epoxy/acid anhydride composition containing 0.1 to 5 parts byweight of a substituted triazine of formula [I] based on 100 parts byweight of an epoxy compound, and 0.7 to 1.2 equivalent of acid anhydridegroup based on 1 equivalent of epoxy group in the epoxy compound.

2. An epoxy/acid anhydride composition in which an epoxy compound has atleast two epoxy groups.

The present invention also relates to an epoxy/acid anhydride resincomposition prepared by thermosetting the epoxy/acid anhydridecomposition of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention is specifically illustrated in moredetail by Examples and Comparative Examples. There are shown below Epoxycompounds (A1) to (A5), Acid anhydrides (B1) to (B4), Substitutedtriazines (C1) to (C10), Commercially available triazines (D1) to (D5),Commercially supplied curing accelerators (E1) to (E3), and Solvents(F1) to (F2) which were employed in respective Examples and ComparativeExamples.

Epoxy compounds (A1) to (A5)

(A1): Bisphenol A type epoxy resin having a molecular weight ofapproximately 380 (Epikote 828 having an epoxy group content of 5.3equivalent/kg, which is a trade name by Yuka-Shell Epoxy, K.K.) wasemployed as it is.

(A2): Tris(hydroxyphenyl)methane triglycidylether (Tactics 742 having anepoxy group content of 6.3 equivalent/kg, which is a trade name by TheDow Chemical Company) was employed as it is.

(A3): Phenol novolak type epoxy resin (Epikote 152 having an epoxy groupcontent of 5.7 equivalent/kg, which is a trade name by Yuka-Shell Epoxy,K. K.) was employed as it is.

(A4): Triglycidyl isocyanurate (TEPIC-L which is a trade name by NissanChemical Industries, Ltd., which is a refined product isolated fromisomers having low boiling points of triglycidyl isocyanurate, and whichhas an epoxy group content of 10.0 equivalent/kg) was employed as it is.

(A5): Bisphenol A type epoxy resin having a molecular weight ofapproximately 900 (Epikote 1001 having an epoxy group content of 2.0equivalent/kg, which is a trade name by Yuka-Shell Epoxy, K. K.) wasemployed as it is.

Acid anhydrides (B1) to (B4)

(B1): Methylhexahydrophthalic anhydride A commercially available reagentwas employed as it is.

(B2): Hexahydrophthalic anhydride A commercially available reagent wasemployed as it is.

(B3): Methylnadic anhydride A commercially available reagent wasemployed as it is.

(B4): Pyromellitic anhydride A commercially available reagent wasemployed as it is.

Substituted triazines (C1) to (C10)

(C1): 2-amino-4,6-bis(monobutylamino)-1,3,5-triazine

Into a four-necked flask equipped with a stirrer, a thermometer and acondenser, 18.5 g (0.1 mol) of cyanuric chloride and 150 ml ofacetonitrile were dissolved at room temperatures, followed by addingdropwise a mixed solution containing of 7.3 g (0.1 mol) of n-butyl amineand 20 g of an ion-exchanged water over 2 hours while maintaining at areaction temperature of not more than 5° C. After that, a solutioncontaining of 10 g (0.1 mol) of potassium hydrogen carbonate and 40 g ofan ion-exchanged water was added dropwise over 1 hour while maintainingthe temperature at not more than 5° C., followed by adding dropwise 15.2g (0.25 mol) of 28% aqueous ammonia at the same temperature and stirringat 50° C. for 4 hours after gradually heating. After that, a product wasfiltered and washed with a large quantity of an ion-exchanged water,followed by drying in vacuo to obtain2-amino-4-butylamino-6-chloro-1,3,5-triazine which is an intermediateraw material. Total quantity of the raw material was dispersed into 100g of an ion-exchanged water, followed by adding 8.1 g (0.11 mol) ofn-butyl amine and raising the temperature to a reflux temperature whilestirring and reacting for 2 hours. Further, a solution containing 4.0 g(0.1 mol) by weight of sodium hydroxide and 20 g of an ion-exchangedwater was dropwise added over 1 hour, followed by allowing to react atthe reflux temperature for 2 hours. After cooling to room temperatures,a product was extracted with 100 ml of toluene, and an organic layer waswashed five times with 80 ml of an ion-exchanged water, followed bydistilling off solvents at reduced pressure to obtain 27 g of2-amino-4,6-bis(monobutylamino)-1,3,5-triazine.

(C2): 2-amino-4,6-bis(monocyclohexylamino)-1,3,5-triazine

In a four-necked flask equipped with a stirrer, a thermometer and acondenser, dissolved 18.4 g (0.1 mol) of cyanuric chloride and 50 ml ofacetonitrile were dissolved at room temperatures while stirring,followed by cooling a system and adding dropwise a mixture containing 35g of an ion-exchanged water, 9.9 g (0.1 mol) of cyclohexyl amine, and10.1 g (0.1 mol) of triethyl amine over 2 hours while maintaining at areaction temperature of not more than 5° C. After further stirring at 5°C. for 2 hours, 70 ml of 28% aqueous ammonia of was added dropwise,followed by stirring at 5° C. for 1 hour, at 20° C. for 1 hour, and at50° C. for 2 hours. After that, temperature was elevated to 60° C., and54.5 g (0.55 mol) of cyclohexyl amine was added and, further, thetemperature was elevated to 70° C., followed by stirring for 3 hours.180 g of an ion-exchanged water was added dropwise, followed by coolingto 10° C. while stirring. A crystal deposited was filtered and washedwith a large quantity of an ion-exchanged water, followed by drying invacuo to obtain 16.5 g of2-amino-4,6-bis(monocyclohexyl-amino)-1,3,5-triazine which is inpowder-state.

(C3): 2,4,6-tris(monobutylamino)-1,3,5-triazine

An autoclave equipped with a stirrer and a thermometer was charged with12.6 g (0.1 mol) of melamine, 200 g of 1,4-dioxane, 72.0 g (1.0 mol) ofn-butyl aldehyde and 2.0 g of 5% Pd-carried active carbon. After theinside of the system was purged with a nitrogen gas, the reaction wasconducted at a reaction temperature of 180° C. and under a hydrogen gas(initial pressure of 40 kg/cm²) for 6 hours. After the completion of thereaction, the autoclave was gradually cooled to room temperature,followed by filtering to remove a catalyst and a solid and distillingoff a solvent to obtain a crude reaction product which is in a viscousliquid. The crude reaction product was dissolved into a mixed solvent ofacetone and hexane which is an eluent, followed by developing through asilica gel column chromatography while successively changing theconcentration in a mixing proportion of 100/1 to 1/100. After isolatinga product, the mixed solvent was distilled off to obtain 19.6 g of2,4,6-tris-(monobutylamino)-1,3,5-triazine which is in a liquid-state.

(C4): 2,4,6-tris(mono-2-ethylhexylamino)-1,3,5-triazine

The same procedures were repeated as in the N-substituted melamine (C3),except that 2-ethylhexyl aldehyde was employed place of n-butyl aldehydeto obtain 25.5 g of 2,4,6-tris(mono-2-ethylhexylamino)-1,3,5-triazinewhich is in a liquid-state.

(C5): 2,4-bis(monobutylamino)-6-(monododecylamino)-1,3,5-triazine

The same procedures were repeated as in the N-substituted melamine (C1),except that n-dodecyl amine was employed in place of the aqueous ammoniato obtain 2,4-bis(monobutyl-amino)-6-(monododecylamino)-1,3,5-triazinewhich is in a solid-state.

(C6): 2,4-bis(monobutylamino)-6-piperidino-1,3,5-triazine

The same procedures were repeated as in the N-substituted melamine (C1),except that piperidine was employed in place of the aqueous ammonia toobtain 2,4-bis(monobutylamino)-6-piperidino-1,3,5-triazine which is inpowder-state.

(C7): 2,4-bis(mono-2-ethylhexylamino)-6-monobutylamino-1,3,5-triazine

The same procedures were repeated as in the N-substituted melamine (C1),except that mono-2-ethylhexylamine was employed in place of n-butylamine, and further n-butyl amine was employed in place of the aqueousammonia to obtain2,4-bis(mono-2-ethylhexylamino)-6-monobutylamino-1,3,5-triazine.

(C8): 2-amino-4,6-bis(2-hydroxyethylamino)-1,3,5-triazine

The same procedures were repeated as in substituted triazine (C1),except that monoethanolamine was employed in place of n-butyl amine toobtain 2,4-bis(amino)-6-(2-hydroxyethylamino)-1,3,5-triazine which is ina powder-state.

(C9): 2,4-bisamino-6-monobutylamino-1,3,5-triazine

In a four-necked flask equipped with a stirrer, a thermometer and acondenser, 184.4 g (1.0 mol) of cyanuric chloride and 800 ml ofacetonitrile were dissolved at room temperature, and a system wascooled, followed by adding dropwise 303.7 g (5.0 mol) of 28% aqueousammonia over 2 hours while vigorously stirring and maintaining reactiontemperature at not more than 10° C. After that, stirring was continuedfor 1 hour after heating to room temperature, followed by graduallyheating to 50° C. and further aging for 4 hours. After cooling to roomtemperature, a product was filtered and washed with a large quantity ofan ion-exchanged water, followed by drying in vacuo to obtain 115 g(yield of 79%) of 2,4-bis(amino)-6-chloro-1,3,5-triazine.

Subsequently, into a four-necked flask equipped with a stirrer, athermometer and a condenser, 14.5 g (0.1 mol) of2,4-bis(amino)-6-chloro-1,3,5-triazine obtained, 100 g of anion-exchanged water and 29.2 g (0.4 mol) of n-butyl amine were added,followed by allowing to react for 6 hours after heating to a refluxtemperature while stirring. After cooling the resulting product to roomtemperature, the product was filtered and washed with a large quantityof an ion-exchanged water, and then washed with toluene, followed bydrying in vacuo to obtain 17.5 g of2,4-bis(amino)-6-monobutylamino-1,3,5-triazine which is in apowder-state.

(C10): 2,4-bis(amino)-6-dibutylamino-1,3,5-triazine

The same procedures were repeated as in the Substituted triazine (C1),except that dibutylamine was employed in place of n-butyl amine toobtain 2,4-bis(amino)-6-dibutylamino-1,3,5-triazine which is in apowder-state.

Commercially available triazines (D1) to (D5)

(D1): Melamine

Melamine (manufactured by Nissan Chemical Industries, Ltd.,powder-state) was employed as it is.

(D2): Benzoguamine

A commercially available reagent was employed as it is.

(D3): Acetoguanamine

A commercially available reagent was employed as it is.

(D4): 2,4-bis(amino)-6-vinyl-1,3,5-triazine

A commercially available reagent was employed as it is.

(D5): N,N-diallyl melamine

A commercially available reagent was employed as it is.

Commercially available curing accelerators (E1) to (E3)

(E1): 2,4,6-tris(dimethylaminomethyl)-phenol

A commercially available reagent was employed as it is.

(E2): 2-ethyl-4-methylimidazole

A commercially available reagent was employed as it is.

(E3): 2-methylimidazole

A commercially available reagent was employed as it is.

Solvents (F1)-(F2)

(F1): methylethylketone

A commercially available special grade reagent was employed as it is.

(F2): methylisobutylketone

A commercially available special grade reagent was employed as it is.

EXAMPLES 1 TO 8 AND COMPARATIVE EXAMPLES 1 TO 10

The above-mentioned Epoxy compounds (A1) to (A5), Acid anhydrides (B1)to (B4), Substituted triazines (C1) to (C10), Commercially availabletriazines (D1) to (D5), Commercially available curing accelerators (E1)to (E3), and Solvents (F1) to (F2) were mixed in a weight ratio as shownin Table 1 and Table 2, followed by conducting an evaluation of a curingactivity, outer appearances in cured resins, and storage stability test.Table 1 shows results of Examples for the present invention, and Table 2shows results of Comparative Examples.

It is to be noted that E/An shown in the Tables shows equivalent ratioof epoxy group with respect to acid anhydride group.

                  TABLE 1                                                         ______________________________________                                        Com-     Examples                                                             ponent   1      2      3    4    5    6    7    8                             ______________________________________                                        Epoxide                                                                              A1    100    100  100  --   --   --   50   --                                        --      --   --    100                                                                              --     --                                                                               --    50                                      --      --   --   --   100                                                                                 --                                                                               --   --                                       --      --   --   --  --      70                                                                                50                                                                                --                                      --      --   --   --  --      30                                                                               --   50                        Acid       B1                                                                                89      89                                                                                89     --                                                                              --     --                                                                               --   --                         anhydride                                                                              B2   --      --   --    101                                                                                82                                                                                  --                                                                              --    67                                      --      --   --   --  --      94                                                                                94                                                                                --                                      --      --   --   --   6      --                                                                              --    4                         E/An           1/1     1/1                                                                                1/1                                                                                1/0.9                                                                            1/0.9                                                                              1/0.8                                                                             1/0.8                                                                                1/1                       ratio                                                                         Accele-                                                                                    C1                                                                               1      --                                                                                --    --                                                                                --   --   --   --                        rator         --2       1                                                                                 --                                                                                 --                                                                                --   --   --   --                                      --     --    0.5                                                                                  --                                                                               --   --   --   --                                      --     --    --      2                                                                                 --                                                                               --   --   --                                      --     --    --    --                                                                                1.5                                                                                 --                                                                                --   --                                      --     --    --    --                                                                                --   1.5                                                                                 --                                                                                --                                      --     --    --    --                                                                                --   --   1.5                                                                                 --                                     --     --    --    --                                                                                --   --   --     1                       Solvent                                                                                    F1                                                                             --     --    --    --                                                                                --   100                                                                                 100                                                                                --                                     --     --    --    --                                                                                --   --   --   100                       ______________________________________                                    

                                      TABLE 2                                     __________________________________________________________________________           Comparative Examples                                                   Component                                                                            1  2  3  4  5  6  7  8  9  10                                          __________________________________________________________________________    A1     100                                                                              100                                                                              100                                                                              100                                                                              100                                                                              100                                                                              100                                                                              100                                                                              100                                                                              100                                         B1              899                                                                              89                                                                               89                                                                               89                                                                               89                                                                               89                                                                               89                                                                                89                                      E/An        1/11                                                                             1/1                                                                             1/1                                                                              1/1                                                                              1/1                                                                              1/1                                                                              1/1                                                                              1/1                                                                              1/1                                        C9           ---1                                                                             --  --                                                                              -- -- -- -- --                                          C10          1--                                                                             --                                                                             --  --                                                                              -- -- -- -- --                                          D1         --  --                                                                            1                                                                                --                                                                              --                                                                              -- -- -- -- --                                          D2         --  --                                                                          --   1                                                                                 --                                                                            -- -- -- -- --                                          D3         --  --                                                                          -- --  1   --                                                                             -- -- -- --                                          D4         --  --                                                                          -- --  --                                                                                1                                                                                --                                                                             -- -- --                                          D5         --  --                                                                          -- --  --                                                                              --    1                                                                               --                                                                             -- --                                          E1         --  --                                                                          -- --  --                                                                              -- --   1                                                                                --                                                                             --                                          E2         --  --                                                                          -- --  --                                                                              -- -- --   1                                                                                --                                        E3         --  --                                                                          -- --  --                                                                              -- -- -- --   1                                         __________________________________________________________________________

(Evaluation)

According to the methods (T1) to (T3) described below, there wereevaluated a storage stability, curing activity, and a polymer (a curedarticle) in an epoxy/acid anhydride composition.

The test results are shown in Table 3.

Curing activity test (T1)

A hot plate equipped with a thermostat was heated and maintained at 200°C., and 0.2 g of respective compositions shown in Tables 1 and 2 weredripped on the hot plate. Then, it was stirred with a bamboo rod havingthe diameter of 3 mm, followed by measuring a period of time(hereinafter, referred to as Gelling Time) until which string of thesolution of the composition is broken to investigate the curingactivity. The Gelling Time at 200° C. is shown such as "○" in not morethan 120 seconds, ".increment." in 121 to 300 seconds, "x" in 300 to1800 seconds, and "x x" in more than 1800 seconds, respectively.

Storage stability test (T2)

Respective compositions shown in Tables 1 and 2 were stored at 23° C.,and a viscosity change with stored days was measured at 25° C. with anEH-type viscometer. Days through which the viscosity immediately aftermixing attains to a double value are shown such as "○" in not less than10 days, ".increment." in 5 to 9 days, "x" in 2 to 4 days, and "x x" inless than 24 hours, respectively.

Polymerization by casting into a mold (T3)

A silicone rubber-made spacer having a cut-shaped "" of 3 mm inthickness and 10 mm in width was placed between two pieces of glassplates which have the length of 140 mm×the width of 240 mm×the thicknessof 3 mm and were coated with a releasing agent, and fixed by a fixingclip so as to prepare a mold for casting a cell having an internalcapacity of the length of 130 mm×the width of 220 mm×the depth of 1 mm.Into the cell, respective compositions shown in Tables 1 and 2 werecast, followed by curing at 100° C. in an oven for 2 hours, and furthercuring at 180° C. for 3 hours. After cooling to room temperatures, thecell for a polymerization by casting into a mold was removed, followedby observing an outer appearance in cured articles from the epoxy resincompositions.

Since compositions in the Examples 6, 7, and 8 of Table 1 contain avolatile organic solvent, the solvent was in advance removed with anevaporator, followed by casting into the cell.

The number of cracks is shown such as "◯" in the quite absence,".increment." in the presence of 1 to 3 pieces, and "x" in the presenceof not less than 4 pieces. Likewise, the number of bubbles is shown suchas "◯" in the quite absence, ".increment." in the presence of 1 to 5pieces, and "x" in the presence of not less than 6 pieces or thepresence of a large mark by boiling of volatile components.

                  TABLE 3                                                         ______________________________________                                                           T3                                                                    T1  T2        crack  bubble                                        ______________________________________                                        Example                                                                       1              ∘                                                                      ∘                                                                            ∘                                                                      ∘                             2              ∘                                                                      ∘                                                                            ∘                                                                      ∘                             3              ∘                                                                      ∘                                                                            ∘                                                                      ∘                             4              ∘                                                                      ∘                                                                            ∘                                                                      ∘                             5              ∘                                                                      ∘                                                                            ∘                                                                      ∘                             6              ∘                                                                      ∘                                                                            ∘                                                                      ∘                             7              ∘                                                                      ∘                                                                            ∘                                                                      ∘                             8              ∘                                                                      ∘                                                                            ∘                                                                      ∘                             Comparative                                                                   Example                                                                       1              x        x               ∘                         2              xx      x             Δ                                  3              xx      ∘                                                                         x        x                                     4              xx      x                x                                     5              xx      x                x                                     6              xx      x                x                                     7              xx      Δ                                                                                x       x                                     8              ∘                                                                      xx            ∘                                                                   ∘                             9              ∘                                                                      xx            ∘                                                                   ∘                             10             ∘                                                                      xx            ∘                                                                   ∘                             ______________________________________                                    

The results in the Table 3 show that all the epoxy/acid anhydridecompositions in the Examples 1 to 8 are more excellent in all the curingactivity, storage stability, and properties in cured articles incomparison with insufficient properties of the epoxy/acid anhydridecompositions in the Comparative Examples 1 to 10.

Possibility of utilization in Industry

The epoxy/acid anhydride composition of the present invention ischaracterized in that it can be prepared to a composition having arelatively low viscosity of 2 to 1000 cps by optionally diluting withorganic solvents, and also, it can be prepared to a composition having arelatively high viscosity of 1000 to 100000 cps by a change to a B stageor by oligomerization thereof through in advance heating withoutemploying solvents after mixing the claimed epoxy/acid anhydridecomposition with a substituted triazine. The storage stability aftermixing is also exceedingly high as an epoxy/acid anhydride composition,for example, such as not less than 7 days at room temperatures, andalso, it is excellent in a stability after mixing with a variety ofliquid-state materials. Further, the epoxy/acid anhydride composition ofthe present invention can be conveniently cured. Curing is carried outat 100 to 200° C. for 1 to 5 hours or so using a usual electric furnace,a hot air-circulating furnace, an infrared rays furnace, a microwavefurnace, and an induction heating furnace, etc. Also in the case that itis employed by diluting with organic solvents, it can be cured in theabove-mentioned conditions or so while evaporating the solvents. Stillfurther, it can be also mixed or impregnated with inorganic fillers suchas silica particles, alumina particles, and glass fibers, or reinforcingmaterials. Also, it is excellent in an adhesive property with woodenmaterials, metallic materials, and a variety of inorganic compounds,etc., and it is high in chemical resistance, whereby, it can be alsoutilized in uses such as vehicles for coatings, coatings and adhesivesfor ceramics, coatings and adhesion for concrete, sealing materials forconstruction and building materials, adhesives for papers and woods,glass cloth/epoxy composite materials, carbon fiber-reinforced compositematerials, boron fiber-reinforced composite materials, fiber-processingagents, binders for medicines and agricultural chemicals, coatingmaterials for the surface of plastics, coating materials for preventingfracture of glass, masking materials for film-forming, and resin-basedencapsulants for electronic parts, etc.

What is claimed is:
 1. An epoxy/acid anhydride composition characterizedby containing, as a curing accelerator, a substituted triazine of theformula [I] ##STR3## (wherein X is an amino group, C₁₋₁₈ monoalkylaminogroup, di C₁₋₁₈ alkylamino group, morpholino group, piperidino group,methyl group or phenyl group; R¹ and R² independently each representC₁₋₁₂ alkyl group, C₁₋₁₂ hydroxyalkyl group, C₄₋₈ cycloalkyl group, C₅₋₉cycloalkylmethyl group or C₅₋₉ methylcycloalkyl group) in an epoxy/acidanhydride composition in which an epoxy compound and an acidanhydride-curing agent are contained.
 2. An epoxy/acid anhydridecomposition as claimed in claim 1, characterized by containing 0.1 to 5parts by weight of a substituted triazine of formula [I] based on 100parts by weight of an epoxy compound, and 0.7 to 1.2 equivalent of acidanhydride group based on 1 equivalent of epoxy group in the epoxycompound.
 3. An epoxy/acid anhydride composition as claimed in claim 1,wherein the epoxy compound is one which has at least two epoxy groups.4. An epoxy/acid anhydride resin composition prepared by curing theepoxy/acid anhydride composition as claimed in claim
 1. 5. An epoxy/acidanhydride composition prepared by mixing an epoxy compound and an acidanhydride-curing agent, the epoxy/acid anhydride composition comprising,as a curing accelerator, 0.1 to 5 parts by weight of a substitutedtriazine of the formula [I] ##STR4## (wherein X is an amino group,C,₁₋₁₈ monoalkylamino group, di C₁₋₁₈ alkylamino group, morpholinogroup, piperidino group, methyl group or phenyl group; R¹ and R²independently each represent C₁₋₁₂ alkyl group, C,₁₋₂ hydroxyalkylgroup, C₄₋₈ cycloalkyl group, C₅₋₉ cycloalkylmethyl group or C₅₋₉methylcycloalkyl group) based on 100 parts by weight of epoxy compound,and containing 0.7 to 1.2 equivalent of acid anhydride group of the acidanhydride based on 1 equivalent of epoxy group in the epoxy compound. 6.An epoxy/acid anhydride resin composition as claimed in claim 3 whereinthe epoxy compound is one which has at least two epoxy groups.